DESCRIPTION: The investigators propose to test the feasibility of developing methods to use a robotic arm, 6 MeV X-ray radiotherapy system for frameless treatment of lesions in the thorax or abdomen, as further described by their abstract: "This project will examine the feasibility of using the Cyberknife R frameless robotic radiosurgery system to treat lesions in the thorax and abdomen. The Cyberknife uses an innovative radiographic image-guidance system to direct the 6 MV x-ray beam to the treatment site without a stereotactic frame. The system is presently configured to treat lesions within the cranium and the cervical spine, but its principle of operation is applicable to treatment sites elsewhere in the body. The proposed study will analyze the fluoroscopic camera capabilities needed for real-time thoracic and abdomenal imaging, will develop image- processing software that can locate radiographic features in the thorax and abdomen, will determine an effective way to use implanted fiducials to mark treatment sites in soft tissue, and will analyze the necessary robot workspace. "The Cyberknife image-guided system removes the conventional frame-based constraints on radiosurgery and introduces the possibility of applying radiosurgery to a wide range of hitherto inaccessible sites throughout the body. This would be a therapeutic advance of great significance." PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE